Simple Interest
MCQs Math


Question:     What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 3% simple interest?


Correct Answer  $4248

Solution And Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3600 × 3% × 6

= $3600 ×3/100 × 6

= 3600 × 3 × 6/100

= 10800 × 6/100

= 64800/100

= $648

Thus, Simple Interest = $648

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $648

= $4248

Thus, Amount to be paid = $4248 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3600

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3600 + ($3600 × 3% × 6)

= $3600 + ($3600 ×3/100 × 6)

= $3600 + (3600 × 3 × 6/100)

= $3600 + (10800 × 6/100)

= $3600 + (64800/100)

= $3600 + $648 = $4248

Thus, Amount (A) to be paid = $4248 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3600, the simple interest in 1 year

= 3/100 × 3600

= 3 × 3600/100

= 10800/100 = $108

Thus, simple interest for 1 year = $108

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $108 × 6 = $648

Thus, Simple Interest (SI) = $648

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $648

= $4248

Thus, Amount to be paid = $4248 Answer


Similar Questions

(1) Find the amount to be paid if Linda borrowed a sum of $5350 at 5% simple interest for 8 years.

(2) Calculate the amount due if Linda borrowed a sum of $3350 at 6% simple interest for 4 years.

(3) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 8% simple interest?

(4) How much loan did Susan borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6497.5 to clear it?

(5) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $7310 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 6% simple interest for 3 years.

(7) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 10% simple interest?

(8) Lisa had to pay $4657.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) Linda took a loan of $4700 at the rate of 7% simple interest per annum. If he paid an amount of $7003 to clear the loan, then find the time period of the loan.

(10) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $12000 to clear the loan, then find the time period of the loan.


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